Pt Dopant: Controlling the Ir Oxidation States toward Efficient and Durable Oxygen Evolution Reaction in Acidic Media

Abstract

Dissolution of Ir oxides in Ir-based catalysts, which is closely linked to the catalyst activity and stability toward the oxygen evolution reaction (OER) in acidic media, is a critical unresolved problem in the commercialization of water electrolysis. Doping foreign elements into the Ir oxides can accomplish an optimal combination of Ir oxidation states that is conducive to the leaching-resistance of active catalytic sites. Here, it is reported that Pt doping into IrOx-based nanoframe is beneficial in both terms of activity and stability. The Pt-doped IrOx-based nanoframe achieves the mass activity of 0.644 A mg(Ir+Pt)(-1)at 1.53V(RHE), which is 15-fold higher than that of the commercial IrO2. During the accelerated durability test, the Ir-IV-to-Ir(III)ratio of 5 is maintained in the presence of Pt dopant to effectively mitigate the degradation of Ir catalyst, leading to the superb catalyst durability in acidic media.